The invention relates to a motor vehicle sheet metal molding made of a non precipitation-hardenable aluminum alloy and a method for producing a motor vehicle sheet metal molding.
It is known to produce highly stressed vehicle components made of aluminum sheet metal, primarily using precipitation-hardenable alloys. The conventional production process is the forming of the aluminum sheet metal of low strength with subsequent ageing for achieving increased strength.
In aluminum alloys in which no strength increase by heat treatment (natural or artificial ageing) can be achieved, an increase of strength can only be achieved via deformation. In order to also be able to produce complex geometries from sheet metals of these alloys, these are usually deformed, like precipitation-hardenable alloys, in a soft state. This means that these non precipitation-hardenable aluminum alloys are for example soft annealed beforehand.
A disadvantage is that pressed parts which are produced by deformation of these soft annealed non precipitation-hardenable aluminum sheet metals only experience a significant increase in strength in regions of high deformability, with the result that the potential for lightweight construction using moldings from economically favorable non precipitation-hardenable aluminum alloys is relatively low. This is also the reason why non precipitation-hardenable aluminum alloys are predominantly used in the chassis area as thick-walled components. Non precipitation-hardenable aluminum alloys are characterized mostly by very good corrosion resistance. In addition, they are often used in non high performance components, however, without the focus on particular lightweight construction.
In order to satisfy the current and future demands for the weight optimization of vehicles, the goal has to be to save weight in all components. This also applies to components made of non precipitation-hardenable aluminum alloys. These aluminum alloys are available as sheet metal of higher or high strength which are produced by cold rolling or by cold rolling with targeted re-annealing. To date, however, no complex components can be produced from these commercially available semi finished parts, even though this would be economically interesting because of the possible weight reduction and the material savings.
The invention is based on the object to provide a high-quality motor vehicle sheet metal molding made of aluminum alloys, and which has improved component properties, and a high strength and/or a higher ductility at the same strength.
The invention is further based on the object, to provide a possibility how to produce a complex component of high strength can be produced by forming from sheet metals made of roll hardened non precipitation-hardenable aluminum alloys.